<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        let number1=+prompt('请输人第一个数：')
        let number2=+prompt('请输人第二个数：')
        let option=prompt("1、请输入要进行的操作：＋、-、*、/\n2、退出")
        let sum=0
        if(option==='+'){
            sum=number1+number2
            alert(sum)
        }
    else if(option==='-'){
        sum=number1-number2
        alert(sum)
    }
    else if(option==='*'){
        sum=number1*number2
        alert(sum)
    }
    else if(option==='/'){
        sum=number1/number2
        alert(sum)
    }
    else if(option==='q'){
       alert('已退出')
    }
    </script>
</body>
</html>